Gasoline Engine Management

Frontmatter

History of the automobile

Abstract

Mobility has always played a crucial role in the course of human development. In almost every era, man has attempted to find the means to allow him to transport people over long distances at the highest possible speed. It took the development of reliable internal-combustion engines that were operated on liquid fuels to turn the vision of a self-propelling “automobile” into reality (combination of Greek: autos = self and Latin: mobilis = mobile).

Karl-Heinz Dietsche, Dietrich Kuhlgatz

Basics of the gasoline (SI) engine

Abstract

The gasoline or spark-ignition (SI) internalcombustion engine uses the Otto cycle and externally supplied ignition. It burns an air/fuel mixture and in the process converts the chemical energy in the fuel into kinetic energy.

Dirk Hofmann, Bernhard Mencher, Werner Häming, Werner Hess

Fuels

Abstract

The most important energy source from which fuels are extracted is petroleum or crude oil. Crude oil was formed over millions of years from the remains of decomposed living organisms and is made up of many different hydrocarbons. High-quality fuels make an important contribution to trouble-free vehicle operation and to low exhaust-gas emissions. The composition and properties of fuels are therefore governed by legal provisions.

Jörg Ullmann, Thorsten Allgeier

Cylinder-charge control systems

Abstract

In the case of a homogeneously operated gasoline engine with a defined air/fuel ratio λ, the output torque and thus the power is determined by the intake-air mass and the injected fuel quantity. The air mass must be proportioned exactly so that λ can be adhered to precisely.

Heinz Fuchs, Bernhard Bauer, Torsten Schulz, Michael Bäuerle, Kristina Milos

Gasoline injection systems over the years

Abstract

The primary purpose of the fuel-injection system is to provide the engine with an air/fuel mixture which is best suited to the prevailing operating state. Over the years, these systems have been continually improved, a significant feature of this improvement being the constant increase in the amount of electronic components used.

Karl-Heinz Dietsche

Fuel supply

Abstract

The function of the fuel-supply system is to deliver fuel at a defined pressure to the fuel injectors. The fuel injectors inject the fuel into the intake manifold (manifold injection) or directly into the combustion chamber (gasoline direct injection). In the case of manifold injection, an electric fuel pump delivers the fuel from the tank to the fuel injectors. In the case of gasoline direct injection, the fuel is likewise delivered from the tank by means of an electric fuel pump; then it is compressed to a higher pressure by a high-pressure pump and supplied to the high-pressure injectors.

Jens Wolber, Peter Schelhas, Uwe Müller, Andreas Baumann, Meike Keller

Manifold injection

Abstract

In gasoline engines with manifold injection, formation of the air/fuel mixture begins outside the combustion chamber in the intake manifold. Since they were introduced to the market, these engines and their control systems have been vastly improved. Their superior fuel-metering characteristics have enabled them to almost completely supersede the carburetor engine, which also operates with external air/fuel-mixture formation.

Anja Melsheimer, Rainer Ecker, Ferdinand Reiter, Markus Gesk

Gasoline direct injection

Abstract

Gasoline direct-injection engines generate the air/fuel mixture in the combustion chamber. During the induction stroke, only the combustion air flows through the open intake valve. The fuel is injected directly into the combustion chamber by special fuel injectors.

Andreas Binder, Rainer Ecker, Andreas Glaser, Klaus Müller

Operation of gasoline engines on natural gas

Abstract

The Association of European Vehicle Manufacturers (ACEA) has undertaken a commitment to reduce average CO2 emissions to 140 g/km by the year 2008. This represents a reduction of 25% when set against the figures recorded back in 1995. Vehicle concepts based on CNG (Compressed Natural Gas) contribute to lowering CO2 emissions. Because natural gas is not yet extensively available at filling stations, it should also be possible for the engine to be run on gasoline.

Thorsten Allgeier, Martin Haug, Roger Frehoff, Michael Weikert, Kai Kröger, Winfried Langer, Jürgen Förster, Jens Thurso, Jürgen Wörsinger

Ignition systems over the years

Abstract

The gasoline, or spark-ignition, engine is an internal-combustion machine that relies on an external source of ignition-energy to run. An ignition spark ignites the air/fuel mixture compressed in the combustion chamber to initiate the combustion process. This ignition spark is generated by a flashover between the electrodes of a spark plug extending into the combustion chamber. The ignition system must generate adequate levels of high-voltage energy to generate the flash - over at the spark plug while also ensuring that the ignition spark is triggered at precisely the right instant.

Karl-Heinz Dietsche

Inductive ignition system

Abstract

Ignition of the air/fuel mixture in the gasoline engine is electric; it is produced by generating a flashover between the electrodes on a spark plug. The ignition-coil energy converted in the spark ignites the compressed mixture immediately adjacent to the spark plug, creating a flame front which then spreads to ignite the mixture in the entire combustion chamber. The inductive ignition system generates in each power stroke the high voltage required for flash - over and the spark duration required for ignition. The electrical energy drawn from the vehicle electrical system battery is temporarily stored in the ignition coil for this purpose.

Walter Gollin

Ignition coils

Abstract

Within the inductive ignition system, the ignition coil is the component responsible for converting the low battery voltage into the high voltage required to generate flashover at the spark plug. The ignition coil operates on the basis of electromagnetic induction: The energy stored in the magnetic field of the primary winding is transmitted by magnetic induction to the secondary side of the coil.

Klaus Lerchenmüller, Markus Weimert, Tim Skowronek

Spark plugs

Abstract

The air/fuel mixture in the gasoline, or spark-ignition, engine is ignited electrically. Electrical energy drawn from the battery is temporarily stored in the ignition coil for this purpose. The high voltage generated within the coil produces a flashover between the spark-plug electrodes in the engine’s combustion chamber. The energy contained in the spark then ignites the compressed air/fuel mixture.

Erich Breuser

Electronic Control

Abstract

“Motronic” is the name of an engine-management system that facilitates open- and closed-loop control of gasoline engines within a single ECU. The first Motronic system went into volume production at Bosch in 1979. Essentially, it comprised the functions of electronic fuel injection and electronic ignition. With the advances made in the field of microelectronics, it has been possible to continuously expand the capabilities of Motronic systems over the course of time. The range of functions has been continuously adapted in response to prevailing demands and the complexity of successive Motronic systems has consequently increased.

Bernhard Mencher, Thorsten Allgeier, Klaus Joos, Andreas Blumenstock, Ulrich Michelt

Sensors

Abstract

Sensors register operating states (e.g. engine speed) and setpoint/desired values (e.g. accelerator-pedal position). They convert physical quantities (e.g. pressure) or chemical quantities (e.g. exhaust-gas concen - tration) into electric signals.

Wolfgang-Michael Müller, Uwe Konzelmann, Roger Frehoff, Martin Mast, Johann Riegel

Electronic control unit (ECU)

Abstract

Digital technology furnishes an extensive array of options for open and closed-loop control of automotive electronic systems. A large number of parameters can be included in the process to support optimal operation of various systems. After receiving the electric signals transmitted by the sensors, the ECU processes these data in order to generate control signals for the actuators. The software program for closed-loop control is stored in the ECU’s memory. The program is executed by a microcontroller. The ECU and its components are referred to as hardware. The Motronic ECU contains all of the algorithms for open and closed-loop control needed to govern the engine-management processes (ignition, induction and mixture formation, etc.).

Martin Kaiser

Exhaust emissions

Abstract

The past few years have witnessed a drastic reduction in pollutant emissions from motor vehicles through the application of technical measures. In the case of passenger cars with gasoline engines, a significant role has been played by vehicles equipped with three-way catalytic converters.

Christian Köhler, Thorsten Allgeier

Catalytic emission control

Abstract

Emission-control legislation lays down limits governing pollutant emissions from motor vehicles. On-engine measures on their own are not enough to comply with these limits. In gasoline engines, catalytic exhaust-gas aftertreatment for the purpose of converting the pollutants has now taken center stage. To this end, the exhaust gas passes through one or more catalytic converters located in the exhaust-system branch before being discharged to atmo - sphere. The pollutants contained in the exhaust gas are converted on the surface of the catalytic converter(s) by chemical reactions into non-toxic substances.

Jörg Frauhammer, Alexander Schenck zu Schweinsberg, Klaus Winkler

Emission-control legislation

Abstract

The US state of California has assumed a pioneering role in efforts to restrict by law pollutant emissions emanating from motor vehicles. The California legislature was spurred into action not least due to the fact that the city of Los Angeles is situated in a basin, preventing wind from dispersing exhaust gases and causing a blanket of haze to descend on and hang over the city. Given the high levels of pollutants in the air, this phenomenon led to the buildup of smog and as a result caused health problems in the city’s population and massive restrictions on visibility.

Bernd Kesch, Ramon Amirpour, Michael Eggers

Exhaust-gas measuring techniques

Abstract

During type-approval testing to obtain General Certification for passenger cars and light-duty trucks, the exhaust-gas test is conducted with the vehicle mounted on a chassis dynamometer. The test differs from exhaust-gas tests that are conducted using workshop/garage measuring devices for in-field monitoring.

Martin-Andreas Drühe

Diagnosis

Abstract

The rise in the sheer amount of electronics in the automobile, the use of software to control the vehicle, and the increased complexity of modern fuel-injection systems place high demands on the diagnostic concept, monitoring during vehicle operation (on-board diagnosis), and workshop diagnosis (Fig. 1). Workshop diagnosis is based on a guided troubleshooting procedure that links the many possibilities of on-board and off-board test procedures and test equipment. As emission-control legislation becomes more and more stringent and continuous monitoring is now called for, lawmakers have now acknowledged onboard diagnosis as an aid to monitoring exhaust emissions, and have produced manufacturer-independent standardization. This additional system is termed the OBD system (On-Board-Diagnosis system).

Matthias Knirsch, Bernd Kesch, Matthias Tappe, Günter Driedger, Walter Lehle

ECU development

Abstract

The Electronic Control Unit (ECU) is the central point from which an electronic system in the motor vehicle is controlled. High demands in terms of quality and reliability are therefore made of ECU development.

Martin Kaiser, Lutz Reuschenbach, Bert Scheible, Eberhard Frech

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